boost/spirit/home/karma/operator/sequence.hpp
// Copyright (c) 2001-2010 Hartmut Kaiser // Copyright (c) 2001-2010 Joel de Guzman // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) #if !defined(SPIRIT_KARMA_SEQUENCE_FEB_28_2007_0247PM) #define SPIRIT_KARMA_SEQUENCE_FEB_28_2007_0247PM #if defined(_MSC_VER) #pragma once #endif #include <boost/spirit/home/karma/domain.hpp> #include <boost/spirit/home/karma/generator.hpp> #include <boost/spirit/home/karma/meta_compiler.hpp> #include <boost/spirit/home/karma/detail/fail_function.hpp> #include <boost/spirit/home/karma/detail/pass_container.hpp> #include <boost/spirit/home/support/info.hpp> #include <boost/spirit/home/support/detail/what_function.hpp> #include <boost/spirit/home/support/attributes.hpp> #include <boost/spirit/home/support/algorithm/any_if.hpp> #include <boost/spirit/home/support/unused.hpp> #include <boost/spirit/home/support/sequence_base_id.hpp> #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/as_vector.hpp> #include <boost/fusion/include/for_each.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/mpl/bitor.hpp> #include <boost/mpl/int.hpp> #include <boost/fusion/include/transform.hpp> #include <boost/mpl/accumulate.hpp> /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { /////////////////////////////////////////////////////////////////////////// // Enablers /////////////////////////////////////////////////////////////////////////// template <> struct use_operator<karma::domain, proto::tag::shift_left> // enables << : mpl::true_ {}; template <> struct flatten_tree<karma::domain, proto::tag::shift_left> // flattens << : mpl::true_ {}; }} /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { namespace traits { // specialization for sequences template <typename Elements> struct sequence_properties { struct element_properties { template <typename T> struct result; template <typename F, typename Element> struct result<F(Element)> { typedef properties_of<Element> type; }; // never called, but needed for decltype-based result_of (C++0x) template <typename Element> typename result<element_properties(Element)>::type operator()(Element&) const; }; typedef typename mpl::accumulate< typename fusion::result_of::transform< Elements, element_properties>::type , mpl::int_<karma::generator_properties::no_properties> , mpl::bitor_<mpl::_2, mpl::_1> >::type type; }; }}} /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { namespace karma { template <typename Elements> struct sequence : nary_generator<sequence<Elements> > { typedef typename traits::sequence_properties<Elements>::type properties; sequence(Elements const& elements) : elements(elements) {} typedef Elements elements_type; struct sequence_base_id; template <typename Context, typename Iterator = unused_type> struct attribute { // Put all the element attributes in a tuple typedef typename traits::build_attribute_sequence< Elements, Context, mpl::identity, Iterator>::type all_attributes; // Now, build a fusion vector over the attributes. Note // that build_fusion_vector 1) removes all unused attributes // and 2) may return unused_type if all elements have // unused_type(s). typedef typename traits::build_fusion_vector<all_attributes>::type type_; // Finally, strip single element vectors into its // naked form: vector1<T> --> T typedef typename traits::strip_single_element_vector<type_>::type type; }; // standard case. Attribute is a fusion tuple template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute, typename Pred1, typename Pred2> bool generate_impl(OutputIterator& sink, Context& ctx , Delimiter const& d, Attribute& attr_, Pred1, Pred2) const { typedef detail::fail_function< OutputIterator, Context, Delimiter> fail_function; typedef traits::attribute_not_unused<Context> predicate; // wrap the attribute in a tuple if it is not a tuple or if the // attribute of this sequence is a single element tuple typedef typename attribute<Context>::type_ attr_type_; typename traits::wrap_if_not_tuple<Attribute , typename traits::one_element_sequence<attr_type_>::type >::type attr(attr_); // return false if *any* of the generators fail return !spirit::any_if(elements, attr, fail_function(sink, ctx, d) , predicate()); } // Special case when Attribute is an stl container and the sequence's // attribute is not a one element sequence template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute> bool generate_impl(OutputIterator& sink, Context& ctx , Delimiter const& d, Attribute const& attr_ , mpl::true_, mpl::false_) const { // return false if *any* of the generators fail typedef detail::fail_function< OutputIterator, Context, Delimiter> fail_function; return !fusion::any(elements, detail::make_pass_container( fail_function(sink, ctx, d), attr_)); } // main generate function. Dispatches to generate_impl depending // on the Attribute type. template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute> bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d , Attribute const& attr) const { typedef typename traits::is_container<Attribute>::type is_container; typedef typename attribute<Context>::type_ attr_type_; typedef typename traits::one_element_sequence<attr_type_>::type is_one_element_sequence; return generate_impl(sink, ctx, d, attr, is_container() , is_one_element_sequence()); } template <typename Context> info what(Context& context) const { info result("sequence"); fusion::for_each(elements, spirit::detail::what_function<Context>(result, context)); return result; } Elements elements; }; /////////////////////////////////////////////////////////////////////////// // Generator generators: make_xxx function (objects) /////////////////////////////////////////////////////////////////////////// template <typename Elements, typename Modifiers> struct make_composite<proto::tag::shift_left, Elements, Modifiers> : make_nary_composite<Elements, sequence> {}; }}} namespace boost { namespace spirit { namespace traits { template <typename Elements> struct has_semantic_action<karma::sequence<Elements> > : nary_has_semantic_action<Elements> {}; }}} #endif